Assessing the Advantages of Sorghum–Haricot Bean Intercropping Over Sole Cropping and Productivity via Competitive Indices in Ethiopia’s Highland Regions

Abstract

There is a critical need to address declining farm size‐related land productivity for sustainable agricultural production in Ethiopia. Intercropping cereals, such as sorghum, with grain legumes can result in a farm‐wide production plan that tackles both financial and environmental concerns. A randomized complete block design (RCBD) experiment was conducted in 2022 and 2023 in Gambella Regional State, southwest highlands of Ethiopia. In the current study, we aimed to assess the effects of plant population ratios and varieties of haricot bean intercropping with sorghum for the better management of resources using various competitive indices. The 13 treatments employed in the study were as follows: 100% sorghums plus 25% haricot bean varieties (Nasir, Awash, and local); 100% sorghums plus 50% haricot bean types (Nasir, Awash, and local); and 100% sorghums plus 75% haricot bean varieties (Nasir, Awash, and local). The findings demonstrated that the Nasir variety, at 50% of the stand count, produced the highest grain yield (2.87 t ha −1 ) of main (sorghum) and intercropped (haricot bean) (2.73 t ha −1 ), which was significantly greater than the sole sorghum by 13.86% and sole haricot bean by 9.44%. As opposed to producing either species as a solitary crop, intercropping sorghum with haricot beans boosted the efficiency of land usage and produced greater total yields. Sorghum intercropped with haricot bean variety Nasir at 50% stand count showed better yield advantages and land use efficiency than another intercropping system, as evidenced by the higher land equivalent ratio (LER) 2.28 and monetary advantage index (MAI) 9463.36 than any other intercropping system. In light of its superior compatibility over other population densities and haricot bean varieties tested in the study, intercropping sorghum with haricot bean variety Nasir at a stand count of 50% is advised for the study region.